Effect of protein kinase C activation and depletion on insulin stimulation of glycogen synthesis in cultured hepatoma cells

Summary Insulin stimulation of glycogen synthesis was nearly abolished in hepatoma cells shortly treated with 4 ß-phorbol 12 \-myristate, 13 -acetate (protein kinase C activation) but remained unmodified in cells chronically treated with the phorbol ester (protein kinase C depletion). Thus, although exogenous activation of protein kinase C results in an inhibition of insulin action, protein kinase C depletion has no influence on this process. The results suggest that, in hepatoma cells, no endogenous activation of protein kinase C may occur in response to the signal triggered by insulin.     

In vitro protein synthesis and α amylase activity in F cells from hepatopancreas ofPalaemon serratus (Crustacea; Decapoda)

In crustaceans, all the steps in the assimilation of food take place in the hepatopancreas. To facilitate the study of this organ, a method for the dissociation of cell types was developed. The hepatopancreas of the prawnPalaemon serratus was mechanically dissociated and the cells separated by Percoll density-gradient centrifugation. The E and R cells had similar densities of around 1.05 g/ml. The F cells were separated into two distinct fractions with densities of 1.075 and 1.082 g/ml. The B cells sedimented at a density of 1.12 g/ml. The ratio between the two populations of F cells was found to vary during the intermolt cycle while B cells disappeared after the molt. When the density gradient fractions were incubated with³H-leucine, incorporation was highest in the F cell fractions. Measurements of -amylase activity, indicated that the two populations of F cells may be derived from the same cell type.     

In vitro amiodarone protein binding and its interaction with warfarin

Summary The binding of amiodarone to human plasma protein and to bovine serum, albumin was studied by three different methods, ultracentrifugation, equilibrium dialysis and fluorescence spectroscopy. The fraction of amiodarone bound to plasma protein amounted to 96.3%. The changes in the binding properties of 1-anilino-naphthalene-8-sulfonate for bovine serum albumin using warfarin and amiodarone as independent inhibitors were analyzed in terms of binding site specificity. The findings indicated that amiodarone and warfarin have two different binding sites on bovine serum albumin, so a noncompetitive inhibition mechanism was indicated. On the basis of our data we cannot exclude other mechanisms of interaction besides direct displacement of one drug by another; nevertheless, metabolite interference between amiodarone and coagulation cofactors may better explain the enhancement of warfarin's pharmacological action in association with amiodarone.This work was partially funded by the CNR (National Research Council, Rome, Italy), Program on Clinical Pharmacology and Rare Diseases. The authors would like to thanks Drs E. Marzi and E. riva for their help.     

Adrenocortical metabolism and plasma corticosterone in soman intoxicated rabbits

Summary The organophosphate neurotoxin soman produced impairments in adrenocortical RNA and protein metabolism. Fasciculate and reticular cell RNA and protein contents were supporessed with sublethal to acutely lethal dosages (20, 30 and 40 g/kg, s.c.) during the acute excitatory phase of intoxication and at 6–8 h post injection. All three dosages produced ca 90% inactivation of plasma cholinesterase. A transient elevation of plasma corticosterone occurred with 20 g/kg soman whereas there was a protracted increase with 30 g/kg. Corticosterone was not significantly elevated with 40 g/kg, but death occurred at 13±4 min. Thus, the magnitude and/or nature of soman-induced metabolic impairments does not appear to prevent adrenal activation.Supported by US Army Medical Research and Development Command Contract DAMD 17-81-C-1202.     

自主式交通系统功能架构优化密度峰值聚类算法

自主式交通系统(autonomous transportation system, ATS)是为应对主动式智慧交通发展趋势而提出的新一代交通系统。为科学合理地构建ATS功能架构,提出了一种面向多属性文本的优化密度峰值聚类算法(density peaks clustering, DPC)。该算法结合交通系统功能架构的基本特征,通过改进的词频-逆向文档频率算法与文本向量空间模型,将多属性文本转化成空间维度坐标。再利用高斯函数和决策值优化DPC算法进行聚类,并结合轮廓系数对聚类结果进行评价。为了检验算法的合理性,在ATS道路自动驾驶场景下,基于道路载运工具运行服务域、交通基础设施管理服务域和交通安全管理服务域的功能数据集进行了算例分析,依据聚类结果绘制功能架构图。架构图由自主感知-自主学习-自主决策-自主响应4层构成,验证了ATS应用场景中功能架构优化算法的可行性和合理性。算例结果表明：该算法的构建具有鲁棒性,算例轮廓系数整体均值为0.84,与原算法相比解决了聚类过程中聚类中心难以划定的问题;与原智能交通系统中的各架构设计相比,该功能架构更具有层次性和逻辑性。该优化算法能够促进新一代交通系统...     

蛋白质组学技术在动物科学中的研究进展

蛋白质组学在后基因组时代以其独特的角度和重要的作用已成为生命科学领域研究的热点内容。动物科学作为生命科学的一个重要分支,其相关研究对人类的生活有着重要意义。为了系统地了解和展望蛋白质组学技术在动物科学中的研究进展,综述了蛋白质组学的概念及其相关技术,归纳和评析了近年来蛋白质组学在动物繁殖、营养、遗传育种和疾病防治方面的研究现状。     

Morphological,biochemical and molecular changes during ectomycorrhiza development

Summary An ectomycorrhiza, a specialized root organ, is the result of a complex interaction leading to a finely-tuned symbiosis between a plant and a compatible ectomycorrhizal fungus. Ultrastructural observations combined with cytochemical and biochemical studies reveal that structural and metabolic changes in the symbiont cells lead to the final phenotype of the active ectomycorrhiza. In the present review these changes are interpreted as changes in gene expression and discussed within the context of ectomycorrhiza development. Recent genetic data indicate that the continued vegetative growth of the ectomycorrhizal hyphae and the root tissues, and their ability to switch to symbiotic organ formation, is basically controlled by developmentally critical genes. The activity of these symbiotic genes during the differentiation of ectomycorrhizas is associated with extensive changes in the concentration of particular polypeptides and protein biosynthesis. The present state of knowledge about the developmental biology of ectomycorrhizas allows only speculation about the events during their development.Puisant mes forces aux sources des galaxies En buvant la sève des arbres M. Jonasz     

Maternal vitamin A restriction alters biochemical development of the brain in rats

Summary The biochemical development of the fetal brain in relation to maternal vitamin A restriction was studied in rats. The vitamin A status of pregnant rats was varied by supplying low, medium and adequate amounts (6, 40, and 100 g retinol/day/kg body weight, respectively) of vitamin A during pregnancy and suckling. The maternal vitamin A restriction caused an altered brain development in terms of tissue weight, DNA, RNA and protein levels, and biosynthesis of DNA and protein from [³H]-thymidine and [³H]-leucine, respectively. A dose-dependent effect of maternal vitamin A restriction on the metabolism of DNA, RNA and protein was noticed in the developing fetal brain of rats.     

孕激素相关子宫内膜蛋白在胃癌早期诊断、预后中的作用

为使用生物信息学系统分析孕激素相关子宫内膜蛋白(Progestagen-associated endometrial protein, PAEP)在胃癌中的早期诊断和预后预测性能及免疫浸润相关性,该研究构建预测模型ROC曲线和偏差校正曲线检验其性能准确性,并通过细胞实验进一步验证分析结果.生信分析结果显示,与正常组织相比,胃癌组织中PAEP的表达较高,在早期（T1期、N0期、M0期）即有统计学意义（P＜0.001）,且诊断胃癌的准确性较高（ROC曲线下面积为0.889）;PAEP高表达的胃癌患者预后较差（P≤0.001）;TNM分期越晚,年龄越大,PAEP表达越高,胃癌患者生存概率越低,偏差校正曲线接近理想曲线（45°线）,显示预测结果良好;PAEP的表达与胃癌中的中性粒细胞、巨噬细胞的浸润水平呈正相关趋势,与B细胞、中央记忆型T细胞、T细胞呈显著的负相关趋势.qRT-PCR和Western blot结果显示,HGC-27、BGC-823、MKN-45、SGC-7901和AGS细胞中PAEP基因转录水平和蛋白表达水平均显著高于GES-1. 结果表明了PAEP 蛋白可用于胃癌诊断和预后的生物标志物,并进行了实验验证,其机制与免疫有关.